Internal code clean up.

PiperOrigin-RevId: 493746870

src/google/protobuf/compiler/cpp/helpers.cc

@@ -198,11 +198,6 @@ std::string IntTypeName(const Options& options, const std::string& type) {
   return absl::StrCat("::", type, "_t");
 }
 
-// Returns true if the message can potentially allocate memory for its field.
-// This is used to determine if message-owned arena will be useful.
-bool AllocExpected(const Descriptor* descriptor) {
-  return false;
-}
 
 
 }  // namespace
@@ -1652,19 +1647,6 @@ FileOptions_OptimizeMode GetOptimizeFor(const FileDescriptor* file,
   return FileOptions::SPEED;
 }
 
-inline bool IsMessageOwnedArenaEligible(const Descriptor* desc,
-                                        const Options& options) {
-  return GetOptimizeFor(desc->file(), options) != FileOptions::LITE_RUNTIME &&
-         !options.bootstrap && !options.opensource_runtime &&
-         AllocExpected(desc);
-}
-
-bool EnableMessageOwnedArena(const Descriptor* desc, const Options& options) {
-  (void)desc;
-  (void)options;
-  return false;
-}
-
 bool HasMessageFieldOrExtension(const Descriptor* desc) {
   if (desc->extension_range_count() > 0) return true;
   for (const auto* f : FieldRange(desc)) {

src/google/protobuf/compiler/cpp/helpers.h

@@ -1020,8 +1020,6 @@ inline OneOfRangeImpl OneOfRange(const Descriptor* desc) { return {desc}; }
 
 PROTOC_EXPORT std::string StripProto(const std::string& filename);
 
-bool EnableMessageOwnedArena(const Descriptor* desc, const Options& options);
-
 bool ShouldVerify(const Descriptor* descriptor, const Options& options,
                   MessageSCCAnalyzer* scc_analyzer);
 bool ShouldVerify(const FileDescriptor* file, const Options& options,

src/google/protobuf/compiler/cpp/message.cc

@@ -1367,13 +1367,7 @@ void MessageGenerator::GenerateClassDefinition(io::Printer* p) {
   format(" public:\n");
   format.Indent();
 
-  if (EnableMessageOwnedArena(descriptor_, options_)) {
-    format(
-        "inline $classname$() : $classname$("
-        "::$proto_ns$::Arena::InternalCreateMessageOwnedArena(), true) {}\n");
-  } else {
-    format("inline $classname$() : $classname$(nullptr) {}\n");
-  }
+  format("inline $classname$() : $classname$(nullptr) {}\n");
   if (!HasSimpleBaseClass(descriptor_, options_)) {
     format("~$classname$() override;\n");
   }

src/google/protobuf/port_def.inc

@@ -534,13 +534,6 @@
 #define PROTOBUF_NODISCARD
 #endif
 
-// Enable all stable experiments if this flag is set.  This allows us to group
-// all of these experiments under a single build flag, which can be enabled in
-// the protobuf.stable-experiments TAP project.
-#ifdef PROTOBUF_ENABLE_STABLE_EXPERIMENTS
-#define PROTOBUF_FORCE_MESSAGE_OWNED_ARENA
-#endif  // !PROTOBUF_ENABLE_STABLE_EXPERIMENTS
-
 #ifdef PROTOBUF_FORCE_COPY_IN_RELEASE
 #error PROTOBUF_FORCE_COPY_IN_RELEASE was previously defined
 #endif